The Shanghai Women's Health Study (SWHS, R01 CA70867) is a population-based cohort study of approximately 75,000 Chinese women who were recruited between 1997 and 2000 and have been followed through multiple in-person follow-up surveys and record linkages. Over the years, data and biological samples collected in the SWHS have been used to evaluate many important etiologic hypotheses and support multiple studies, including several NCI-sponsored cohort consortium projects. In this renewal application, we request continued support for this unique cohort study to evaluate a new set of hypotheses and confirm, with a larger sample size and improved exposure assessments, some of the promising associations identified during the current grant period. We will continue to analyze survey data to evaluate dietary and other lifestyle factors in relation to cancer risk with a specific focus on evaluating dietary protective factors, such as regular consumption of soyfood, tea, and ginseng. With additional follow-up of the SWHS, we will have, for the first time, adequate statistical power to investigate less common cancers, such as cancers of the ovary, corpus uteri, and pancreas, as well as subtypes of common cancers. Using a case-cohort study design, we propose to investigate urinary prostaglandin E2 metabolite (PGE-M), as well as telomere length and mitochondrial DNA copy number measured in peripheral white blood cells in relation to the risk of cancer, and further identify lifestyle determinants for urinary PGE-M and blood cell telomere length. Finally, we will evaluate the utility of validated genetic markers in assessing an individual's risk for breast cancer. The renewal of this cohort study will enable continued follow-up of this cohort for five more years and provide adequate numbers of cancer cases for investigating the hypotheses proposed in this application and for future studies. Because of its size, setting, and inventory of biological specimens and epidemiologic/clinical data, the SWHS provides an exceptional opportunity to address many significant hypotheses that cannot be adequately investigated in any other existing cohort studies. The results from this study will have significant implications for the primary and secondary prevention of common cancers in both Western and Asian women.